Lift swing furnace

ABSTRACT

An elevatable annular induction furnace mounted on the outer one of a pair of vertically oriented tubular supports to permit raising and pivoting the furnace for selectively heating alternate ones of a plurality of metal containing crucibles. The supports are coupled by a pin and slots to ensure proper alignment of the furnace and the crucibles.

United States Patent 11 1 Landis et al.

14 1 Aug. 26, 1975 LIFT SWING FURNACE 1.879.43l 9/1932 Northrup 13/26 l,95l,88l 3 l934 N th ..l 26 [75] lnventors: James P. Landis, Wauwatosu, Wi s.; or mp 3/ Robert 0. Williams, Grosse Point. Mich Primary Examiner-R. N. Envall, Jr. I Attorney, Agent, or Firm-Fred Wiviott [73] Ass1gnee: Pillar Corporatlon, Mllwaukee, W1s.

22 F] d: 6,1974 I la June 57 ABSTRACT [2|] Appl. No.: 476,853

- An elevatable annular 1nduct1on furnace mounted on the outer one of a pair of vertically oriented tubular [52] US. (,l. 13/26 supports to r it raising and pivoting the furnace for [51] Int. Cl. H05b 5/00 Selectively heating alternate ones f a phlmlity f [58] Field of Search.... 13/26, 27, 1 meta] containing crucibles The supports are Coupled by a pin and slots to ensure proper alignment of the References Cited furnace and the crucibles.

UNlTED STATES PATENTS 1,752,887 4/1930 Chuttcr l3/26 9 3 Drawmg F'gures fl l 1 I I LIFl SWING FURNACE BACKGROUND OF THE INVENTION This invention relates generally to the art of electric induction heating furnaces and in particular to an induction heating furnace which is employed to selectively heat the metallic contents of a plurality of crucibles. One prior art apparatus for heating successive crucibles of metal employs a carriage to successively move one crucible at a time into position below a vertically movable heating furnace. This apparatus was not wholly satisfactory, however, because special carriages were required and, in addition, the lateral movement of molten metal into or out of proximity with a furnace is a time-consuming procedure and metal spillage is common. I

Another type of prior art induction melting furnace includes a pair of crucible openings in a dual coil structure wherein crucibles are raised or lowered into one of the coil openings. In such apparatus, conventional lifting tongs which encircle the crucibles cannot be in position during the melting cycle. In addition, such apparatus require special apparatus such as a pit in the floor and hydraulic lifting cylinders which can be damaged by molten metal if crucibles break either during heating or crucible movement.

SUMMARY OF THE INVENTION It is a primary object of the present invention to provide an induction furnace which may be safely and rapidly moved between operative positions relative to a plurality of molten metal containing crucibles.

A further object of the invention is to provide apparatus for melting metal in successive crucibles wherein displacement of the crucibles is not required.

A further object of the present invention is to provide a compact and relatively simple induction furnace system for melting metal contained in a plurality of crucibles.

A still further object of the present invention is to provide an induction heating system wherein the lift tongs for the molten metal containing crucibles can be put into lifting position prior to the heating operation.

Yet another object of the invention is to provide a multiple crucible induction melting furnace which permits the direct transfer of crucibles to a pouring location without intervening handling steps.

How these and other objects of the present invention are accomplished will be described in detail in the following specification taken in conjunction with the drawings. Generally, however, the preferred form of the invention comprises a generally vertical support post upon which an induction heating coil is mounted for vertical movement to a preselected vertical position whereupon the coil may be pivoted into position above alternate crucibles and selectively lowered into an operative position therearound and guide means for permitting vertical coil movement only when the latter is in axial alignment with a crucible.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevational view, partly in section, of a preferred embodiment of the present invention;

FIG. 2 is a front view of the apparatus shown in FIG.

FIG. 3 is a top plan view of the apparatus shown in FIG. 1.

DESCRIPTION OF A PREFERRED EMBODIMENT FIGS. 1 and 2 show an induction melting furnace according to the present invention to generally include a support base 12, a pair of crucible pedestals and 15' for supporting crucibles and 20, a furnace support assembly and an induction melting furnace 40. While the illustrated embodiment shows a single furnace 40 and two crucible stands 15, the assembly may include larger numbers of crucible supports and/or furnaces without deviating from the inventive concept.

Base 12 may comprise a relatively flat metal plate having a vertical lip 13 at its outer edge so as to contain molten metal in the event of crucible failure or spillage. A generally T-shaped support frame 13 is disposed along one side and across the center of the base 12 and serves as the point of attachment between the furnace support 30 and base 12. Frame 13 also divides the base 12 into two tray-like sections 14. Disposed within each section 13 and equidistantly from furnace support 30 is an annular collar 16 for receiving the lower end of one of the crucible pedestals 1S.

Furnace support assembly 30 includes a first vertical support post 32 and a concentric sleeve 33 of slightly larger diameter which is telescopingly received thereover. Sleeve 33 may be slightly shorter than post 32 and may be suitably vented, such as at 34. A lift bracket 35 may be secured to the upper end of sleeve 34 for being coupled to a lifting crane or hoist. Sleeve 33 also includes two vertical slots 36 and 37 extending upwardly from the bottom of sleeve 35 to a point intermediate its ends. A guide pin 38 extends into post 32 and is adapted to be received within slots 36 and 37 which have a width slightly greater than the body of pin 39. While the diameter of sleeve 33 relative to post 32 is such as to provide a relatively loose fit, a guide bearings 39 is disposed intermediate the ends of post 32 and at the upper end thereof and each has a slightly larger diameter than the post 32 to provide a sliding fit with sleeve 33.

The induction melting furnace 40 generally includes an annular, open ended coil 43 which may be suitably energized from a power source (not shown) by conductors 44 which may be suitably water cooled. The coil 43 may be provided with a refractory lining 45 which defines a generally cylindrical crucible receiving area. An annular housing 46 may be provided in surrounding relation to furnace 40. Furnace 40 may be secured to support 30 by a pair of support assembly brackets 51 connected respectively to the housing 46 and to sleeve 33. A handle 53 may be attached to the housing 46 at the side thereof opposite sleeve 33 to facilitate swinging furnace 40 about the axis of support column 30.

Those skilled in the art will appreciate that when energized, the coil 43 will induce secondary currents in the metal 55 within crucible 20 which sufficiently heat the same to its fusion temperature. In the illustrated embodiment, there are two crucibles 20 and 20' for containing molten metal 55 to be heated by furnace 40. FIG. 2 shows furnace 40 in operating position around crucible 20, while crucible 20' is in the ready position. When it is desired to move furnace 40 into an operative position relative to crucible 20', sleeve 33 is raised by a hoist or crane (not shown) so that the lower end of sleeve 33 is above guide pin 36. Slot 36 guides the upward movement of sleeve 33 and prevents furnace 40 from disturbing crucible 20. When furnace 40 is raised over crucible 20, sleeve 33 is rotated to place furnace 40 over crucible 20. The slot 37 is then in registry with pin 38 for guiding'furnace 40 to an operative position around crucible 20'. In the illustrated example, the angle between the vertical axis of crucible 20, support 30 and crucible 20 is 90, so that slots 37 in sleeve 33 would be separated by an arc of 90, although it will be appreciated that any suitable angle may be employed with the slots subtending the same are as that between the crucibles 20 and 20. I

Referring once again to FIG. 1, a pouring cradle on lift tongs 60 for crucible 20 is shown surrounding crucible pedestal while furnace 40 is heating the material in crucible 20. Once furnace 40 is removed, the lifting tongs may be raised to engage crucible for transporting it to a pouring station.

- .Whileonly a single embodiment of the invention is shown and described, it is not intended to be limited thereby. For example, a single fumace 40 as illustrated and described could be employed with more than two crucibles.'ln this case, the crucibles 'and guide slots would be equilaterally arranged with respect to the axis of support system 30. A further'possible modification "includes providing two furnaces 40 with multiples of two crucibles. For example, if two furnaces were arranged at 180 angles with respect to the axis of support 30, four crucibles could be arranged'at 90 angles with "respect to the support system 30. Naturally, if brackets tion above an alternate crucible or by moving the furnace 40 in a vertical are between alternate positions above crucibles. In the latter event, the furnace 40 would, in effect, be flipped over. Accordingly, while the invention has been described in connection with a particular preferred embodiment thereof, the invention is not to be limited thereby but is to be limited solely by the claims which follow.

We claim: 1. An induction furnace including an open-ended electromagnetic coil, at least two container means disposed in horizontal spaced relation, support means, said coil being mounted on said support means for generally vertical movement between first position in surrounding relation to one of said containers to a second position vertically above said one container, said support means including translating means for moving said furnace to a third position above the other container, said support means being operative to permit said coil to be lowered into surrounding relation with said other container when in its third position.

2. The invention set forth in claim 1 and including guide means for preventing translational movement of said coil when the latter is below said second position.

3. The invention set forth in claim 2 wherein said furnace support means includes pivotal means, said furnace being mounted on said pivotal means for movement between said second and third positions.

4. The invention set forth in claim 3 wherein said furnace support means comprises a fixed vertical support post and a second concentric vertical sleeve means slid able over said support post, said furnace being secured to said sleeve and having its axis displaced from the axis of said sleeve and post and being generally parallel thereto.

5. The invention set forth in claim 4 wherein said guide means comprises at least two vertical slots formed in said sleeve means extending upwardly from the base thereof and pin means extending radially from said post means for being received in one of said slot means when said furnace is at an elevation below that of its second position, the lower end of said sleeve means being above said pin means when said furnace is elevated to its second position to permit lateral movement thereof.

6. The invention set forth in claim 5 and including a support base, said support post being vertically mounted on said support base, a plurality of crucible support means disposed on said base means and equispaced relative to the axis of said support post.

7. The invention set forth in claim 6 including two container means and two slot means in said sleeve means, and wherein the angle between the axis of said sleeve means and'said two container means equals the angle between the axis of said sleeve means and said slot means.

8. The invention set forth in claim 6 wherein the number of said slot means equals the number of said container means and wherein the angle between the axis of said sleeve means and any two adjacent container means equals the angle between the axis of said sleeve means and any two adjacent slots therein.

9. In combination,

vertically extensible support'means, an open-ended induction coil mounted on said support means, the axis of said coil being displaced from the axis of said support means, a plurality of crucible means arranged aboutsaid support means,

means associated with said support means for translating said coil when said furnace means are in a first elevated position, and

means associated with said support means for restraining lateral movement of said coil when said furnace means are at an elevation lower than said first position.

Dedication 3,901,999.James P. Landz's, Wauwatosa, Wis., and Robert 0. W z'llz'ams, Grosse Point Woods, Mic LIFT SWING FURNACE. Patent dated Aug. 26, 1975. Dedicat' 1977, by the assignee, Pz'llar' Uorpomtz'on. Hereby dedicates to the Public the remaining term of said patent.

[Oficz'al Gazette Mamh 14, 1.978.]

Dedication v 3,901,999.James P. Lamolz's, Wauwatosa, Wis., and Robert 0. Williams, Grosse Point Woods, Mich. LIFT SWING FURNACE. Patent dated Aug. 26, 1975. Dedication filed Nov. 2, 1977, by the assignee, Pz'ZZaw Oarpomtz'on. Hereby dedicates to the Public the remaining term of said patent.

[Ofiicz'al Gazette March 14, 1.978.] 

1. An induction furnace including an open-ended electromagnetic coil, at least two container means disposed in horizontal spaced relation, support means, said coil being mounted on said support means for generally vertical movement between first position in surrounding relation to one of said containers to a second position vertically above said one container, said support means including translating means for moving said furnace to a third position above the other container, said support means being operative to permit said coil to be lowered into surrounding relation with said other container when in its third position.
 2. The invention set forth in claim 1 and including guide means for preventing translational movement of said coil when the latter is below said second position.
 3. The invention set forth in claim 2 wherein said furnace support means includes pivotal means, said furnace being mounted on said pivotal means for movement between said second and third positions.
 4. The invention set forth in claim 3 wherein said furnace support means comprises a fixed vertical support post and a second concentric vertical sleeve means slidable over said support post, said furnace being secured to said sleeve and having its axis displaced from the axis of said sleeve and post and being generally parallel thereto.
 5. The invention set forth in claim 4 wherein said guide means comprises at least two vertical slots formed in said sleeve means extending upwardly from the base thereof and pin means extending radially from said post means for being received in one of said slot means when said furnace is at an elevation below that of its second position, the lower end of said sleeve means being above said pin means when said furnace is elevated to its second position to permit lateral movement thereof.
 6. The invention set forth in claim 5 and including a support base, said support post being vertically mounted on said support base, a plurality of crucible support means disposed on said base means and equi-spaced relative to the axis of said support post.
 7. The invention set forth in claim 6 including two contaIner means and two slot means in said sleeve means, and wherein the angle between the axis of said sleeve means and said two container means equals the angle between the axis of said sleeve means and said slot means.
 8. The invention set forth in claim 6 wherein the number of said slot means equals the number of said container means and wherein the angle between the axis of said sleeve means and any two adjacent container means equals the angle between the axis of said sleeve means and any two adjacent slots therein.
 9. In combination, vertically extensible support means, an open-ended induction coil mounted on said support means, the axis of said coil being displaced from the axis of said support means, a plurality of crucible means arranged about said support means, means associated with said support means for translating said coil when said furnace means are in a first elevated position, and means associated with said support means for restraining lateral movement of said coil when said furnace means are at an elevation lower than said first position. 